On Thu, 2019-06-06 at 09:08 +0800, Kefeng Wang wrote:

On 2019/6/5 22:42, Pali Rohár wrote:

quoted

On Wednesday 05 June 2019 22:24:28 Kefeng Wang wrote:

quoted

IS_ERR(_OR_NULL) already contain an 'unlikely' compiler flag,
so no need to do that again from its callers. Drop it.

Hi! I already reviewed this patch and rejected it, see:
https://patchwork.kernel.org/patch/10817475/

OK, please ignore it.

I think the stated reason of better readability isn't
particularly sensible as the object code produced is
actually slightly larger.

x86-64 defconfig (gcc 8.3.0)

$ size drivers/input/mouse/alps.o*
   text	   data	    bss	    dec	    hex	filename
  29416	     56	      0	  29472	   7320	drivers/input/mouse/alps.o.new
  29432	     56	      0	  29488	   7330	drivers/input/mouse/alps.o.old

Also if this unlikely is _really_ useful, perhaps the
!IS_ERR immediately after could also use likely as the
test seems only done for an OOM condition.

quoted

quoted

Cc: "Pali Rohár" <redacted>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: linux-input@vger.kernel.org
Signed-off-by: Kefeng Wang <redacted>
---
 drivers/input/mouse/alps.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/input/mouse/alps.c b/drivers/input/mouse/alps.c
index 0a6f7ca883e7..791ef0f826c5 100644
--- a/drivers/input/mouse/alps.c
+++ b/drivers/input/mouse/alps.c

@@ -1478,7 +1478,7 @@ static void alps_report_bare_ps2_packet(struct psmouse *psmouse,
 		/* On V2 devices the DualPoint Stick reports bare packets */
 		dev = priv->dev2;
 		dev2 = psmouse->dev;
-	} else if (unlikely(IS_ERR_OR_NULL(priv->dev3))) {
+	} else if (IS_ERR_OR_NULL(priv->dev3)) {
 		/* Register dev3 mouse if we received PS/2 packet first time */
 		if (!IS_ERR(priv->dev3))
 			psmouse_queue_work(psmouse, &priv->dev3_register_work,